Mechanosensory hair cells express two molecularly distinct mechanotransduction channels

Nat Neurosci. 2017 Jan;20(1):24-33. doi: 10.1038/nn.4449. Epub 2016 Nov 28.

Abstract

Auditory hair cells contain mechanotransduction channels that rapidly open in response to sound-induced vibrations. We report here that auditory hair cells contain two molecularly distinct mechanotransduction channels. One ion channel is activated by sound and is responsible for sensory transduction. This sensory transduction channel is expressed in hair cell stereocilia, and previous studies show that its activity is affected by mutations in the genes encoding the transmembrane proteins TMHS, TMIE, TMC1 and TMC2. We show here that the second ion channel is expressed at the apical surface of hair cells and that it contains the Piezo2 protein. The activity of the Piezo2-dependent channel is controlled by the intracellular Ca2+ concentration and can be recorded following disruption of the sensory transduction machinery or more generally by disruption of the sensory epithelium. We thus conclude that hair cells express two molecularly and functionally distinct mechanotransduction channels with different subcellular distributions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Hair / metabolism
  • Hair Cells, Auditory / cytology*
  • Mechanotransduction, Cellular / genetics
  • Mechanotransduction, Cellular / physiology*
  • Membrane Proteins / metabolism
  • Mice, Knockout
  • Mutation / genetics
  • Stereocilia / genetics
  • Stereocilia / metabolism*

Substances

  • Membrane Proteins
  • Calcium